WATCH: This is what a world champion whistler sounds like

For some, it’s an idle way to pass the time or hail down a taxi in a pre-app world. For others it’s a tinny annoyance that you wish the person doing it would cease with immediate effect. In early China, the technique was used a nonverbal language. The denizens of the Greek town Antia were fluent in it as a language until even as late as 1982. Whistling, that thing you wish you could do or wish you could stop hearing.

Christopher Ullman is perhaps the world’s greatest whistler, having been four times the US and International whistling champion. He doesn’t just merely puff a shrill whine through his pursed lips, also using his tongue and teeth to mimic different instruments or add embellishments to a song he is interpreting.

National Geographic recently carried out a short interview with him, where he reveals his techniques and explains what it takes to be a world champion. Take a look at the video below: